As a commercial way of producing ethanolamine by the reaction of ethylene oxide with ammonia, a process which comprises reacting ethylene oxide (EO) with aqueous ammonia (aqueous ammonia process) and a method which comprises reacting ethylene oxide (EO) with liquid ammonia using a zeolite catalyst (catalyst process) have been known (for example, JP 2005-8536 A).
Among these, in the aqueous ammonia process, water serves as a catalyst, and production ratios of a monoethanolamine (MEA), a diethanolamine (DEA), and a triethanolamine (TEA) can be changed by changing a ratio of ethylene oxide to ammonia (molar ratio of EO/NH3).